Program Control; Heater Relays - Miele W1903 User Manual

Technical Information
4.18

Program Control

The Program Control consist of the Electronic Control Unit (Upper
Electronic) and the Power Supply Electronic Unit (Lower Electronic).s
Functions of the Electronic Control Unit include:
Precise program and component control
Monitoring circuits (i.e. motor speed, temperature etc...)
A Fault Finding and Service Mode
Program Mode (W1966 & W1986)
Functions of the Power Supply Electronic include:
Providing the Electronic Control Unit with the "zero crossover point
signal" (used for timing)
Component switching (via relays and thyristors)
On models equipped with the Delayed Start feature, a third electronic is
installed. This Electronic provides the delay control and also contains the
numeric LEDs, for displaying the remaining wash time to the user.
Important!
If an Electronic is suspected to be faulty; the "Electronic Test" procedure
must be performed. Refer to Section 5.13 – Determining Which
Electronic Requires Replacement.
4.19

Heater Relays

Switching of the two Heater Elements is performed via two relays. Both
relays are controlled by the Electronic, and are energized when:
1. The program calls for heating AND
2. The water level is at an acceptable level (as determined by the Level
Switch).
Service Tip:
Even in the Service Mode the Water Level Switch must be satisfied
before the Heating Relays & Elements can be powered on.
W1900 Series Clothes Washers
34